[all-commits] [llvm/llvm-project] 097789: [SimpleLoopUnswitch] Perform poison query before t...

[Nikita Popov via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 09778940d1aea0cd3ff99df47cd2dc2fe5b09bb9
      https://github.com/llvm/llvm-project/commit/09778940d1aea0cd3ff99df47cd2dc2fe5b09bb9
  Author: Nikita Popov <npopov at redhat.com>
  Date:   2023-01-02 (Mon, 02 Jan 2023)

  Changed paths:
    M llvm/lib/Transforms/Scalar/SimpleLoopUnswitch.cpp

  Log Message:
  -----------
  [SimpleLoopUnswitch] Perform poison query before transform

I think this doesn't make any difference right now, but once
we take into account that branch on undef is UB in
programUndefinedIfUndefOrPoison() the new position of the branch
would imply that the condition can't be poison, which would
defeat the purpose of the freeze insertion here. We need to
perform the check before the branch is moved.